The invention relates to a hand-held power tool, in particular a portable hand-held power tool such as a motor chain saw, a cut-off machine, a trimmer, a blower or the like. The power tool comprises a drive unit arranged in a tool housing. The drive unit has an internal combustion engine with a cylinder provided with a combustion chamber and a spark plug. The combustion chamber is delimited by a piston driving the crankshaft. A central control unit controlling the drive unit is provided which central control unit comprises a microprocessor and is connected to the spark plug via an ignition control unit. As a function of the rotary speed of the crankshaft, the central control unit triggers a spark at the spark plug at an adjusted ignition timing. A data storage device is connected to the central control unit and an energy supply device for providing the required electric energy is provided.
Such portable hand-held power tools are generally known. In the interior of the tool housing a drive unit comprising an internal combustion engine is provided. The internal combustion engine has a cylinder with a combustion chamber and a spark plug. The combustion chamber is delimited by a piston that drives the crankshaft in a crankcase. The combustion chamber has moreover a spark plug that provides a spark by means of an ignition unit as a function of the rotary speed and rotary position of the crankshaft at a suitable ignition timing in order to ignite the taken-in fuel/air mixture in the combustion chamber. For this purpose, the drive unit has correlated therewith an electronic central control unit with a microprocessor that is utilized, for example, for calculating the ignition timing and that has connected thereto a data storage device for its operation. The microprocessor can also fulfill other tasks and/or can control other devices such as an injection valve and/or can read sensor values. The required energy for operating the central control unit and for generating the spark or for powering other consumers is provided by an energy supply unit that can be in the form of a generator driven by the crankshaft and delivering at least one voltage wave for each crankshaft rotation.